1. Field of the Invention
The present invention relates to a liquid crystal display device and a method for driving the liquid crystal display device.
2. Description of the Related Art
It is known that liquid crystal display devices are roughly divided into two kinds of liquid crystal display devices: transmissive liquid crystal display devices and reflective liquid crystal display devices.
In a transmissive liquid crystal display device, a backlight such as a cold cathode fluorescent lamp is used, and a state in which light from the backlight is transmitted through a liquid crystal and output to the outside of the liquid crystal display device or a state in which light is not output is selected using optical modulation action of liquid crystal, whereby bright and dark images are displayed. Further, those displays are combined to display an image.
In a reflective liquid crystal display device, a state in which external light, in other words, incident light is reflected at a pixel electrode and output to the outside of the device or a state in which incident light is not output to the outside of the device is selected using optical modulation action of liquid crystal, whereby bright and dark images are displayed. Further, those displays are combined to display an image.
A color filter method and a field-sequential method are known as display methods of liquid crystal display devices. Liquid crystal display devices in which images are displayed by a field-sequential method are provided with a plurality of light sources exhibiting different colors (e.g., red (R), green (G), and blue (B)). A desired color is produced in such a manner that the plurality of light sources exhibiting different colors sequentially emit light and transmission of a light of each color is controlled in each pixel, so that color display is performed. That is, a field-sequential method is a method in which a desired color is realized with division of the display period into respective display periods for respective lights of colors.
Patent Document 1 discloses a liquid crystal display device in which images are displayed by a field-sequential method. Specifically, Patent Document 1 discloses a liquid crystal display device in which pixels each include a transistor for controlling input of an image signal, a signal storage capacitor for holding the image signal, and a transistor for controlling transfer of electric charge from the signal storage capacitor to a display pixel capacitor. In the liquid crystal display device having this structure, writing of an image signal to the signal storage capacitor and display corresponding to electric charge held at the display pixel capacitor can be performed at the same time.